I have never had to use an adjustable prop valve on a car that had properly designed and sourced parts. Buy a correctly sized good MC with a known bias instead of a $15 piece from Autozone, match the brake kit to the car (weight, speed, tire size, etc.) and pay attention to things like bore sizes and it just works. Hint: Wilwood and other manufacturers calipers may look the same, but the bore sizes are often quite different and as a result, they don't work the same.